Electrical resistance unit



Sept. 13 1938. 1.. F. MUTER 2,130,148

ELECTRICAL RESISTANCE UNIT Filed July 6, 1936 Les 16 Jim/6 1 Patented Sept. 13, 1938 UNITED STATES PATENT OFFICE ELECTRICAL RESISTANCE UNIT Leslie F. Mater, 01110880, Ill.

Application July 6, 1936, Serial No. 8 9,210

5Claims.

This invention relates to electrical resistance units generally. More particularly this invention relates to metal casings for, holding and/or enclosing and attaching resistance elements to supports.

An object of this invention is to provide a resistance unit with a casing adapted to enclose the resistance element, said casing being provided with integral tongue-like members which are adapted to be inserted into suitable slots formed in a supporting panel or chassis and twisted to fasten said casing to the supporting panel or chassis in a firm and vibration-free manner, yet permitting said resistance unit to be easily removed from the supporting panel or chassis, if desired.

Another object of this invention is to provide a resistance unit casing member formed of an elongated sheet of metal and having two or more tongues formed therein which are adapted to fit into slots formed in a supporting member, and engage sides of said slots in cam-like fashion to hold the resistance unit on said supporting member in a firm and vibration-free manner.

A further object of this invention is to provide a resistance unit with a casing member adapted to be connected to one terminal of the resistance unit, and having tongue-like extensions formed integral with the casing member for fastening the resistance unit to the metal chassis of an instrument in which the resistance unit is to be used, in a firm manner so that an electrical circuit between the resistance 'unit and the metal chassis is maintained without \interruption'or partial interruption.

Other and further objects of this invention will be apparentfrom the following specification and the claims.

In accordance with this invention I provide a resistance unit of the metal'jacketed type-with convenient and economical fastening means whereby the resistance unit may be attached to and fastened in place upon a panel or chassis without the use of unusual or special tools.

My invention is especially adapted to use with resistance units which are to be used in sensitive electrical circuits. suchas, electric discharge device ampliflers, in which even the slightest movement between electrical. contacts is reproduced in the form of noise or interference in the amplifier reproducer. For example, in amplifier systems a large number of the resistance units employed are grounded or connected to the metal chassis, of the amplifier; This is often done through the fastening device of the resistance unit inasmuch as the winding- Since the resistance unit fastening device or devices are part of the electrical circuit vibration in the fastening device or devices will 5 cause undesirable interference in the operation of the electrical circuit.

Furthermore, even in resistance units which are supported on a metal chassis by a metal frame or jacket which is not included in the electrical l0 circuit of the amplifier, if the resistor fastening device or devices are loose or become loose through vibration, as in automobile radio receivers, for example, interference potentials develop at these loose contacts. My invention eliminates all of these and other difficulties. Resistance units mounted in accordance with my invention cannot under any ordinary conditionsvibrate loose because of the cam- .like action that is produced between surfaces of the fastening tongue or tongues and the receiving 1 slot or slots of the chassis.

These and other features of my invention will be apparent to those skilled in the art to which this invention relates from the following speciflcation and the drawing in which, briefly, Fig. 1 illustrates a resistance unit made in accordance with this invention, in mounted position; Figure 2 is a view showing the manner in which the mounting tongues of the resistance unit casing,are deformed to support the unit; Figure 3 is a view showing a mounting tongue of the resistance unit casing before twisting; Figure 4 illustrates another form of the resistance unit mounting tongue and Figures 5 and 6illustrate sections of the resistance unit casing blank.

Referring to Figure 1 of the'drawing in detail, reference numeral l0 designates an elongated metallic casing bent into a channel-like hollow member for housing the resistance winding i2 40 wound upon a suitable core l2a, therein. The winding I! of the resistance unit is insulated from the casing III by the sheet-like insulating material II, the ends of which project out of the casing It as shown. One end of the winding i2 contacting the terminal ll of the resistance unit may be in electrical contact with the casing l0. The other terminal If is insulated from the casing. Where desired, a plurality of terminals such as I and I5 may be'provided to the resistance unit to enable the user to make electrical connections to various parts of the resistance unit. This is especially desirable where the resistance unit is employed as a voltage divider.

The ends of the resistance unit casing ill are provided with tongues l6 and I1 adapted to be bent substantially at right angles to the base of the casing. The purpose of these tongues is to support the resistance unit upon and/or flat against the panel member 22 which is provided with two slots l8 and I9 adapted to receive the tongues i6 and-I1, respectively. The panel mem- -ber may be part of the metal chassis of a radio corresponding parts of the tongues l and il are'wide. The tongue 16, for example, extends through the slot I 8 a suflicient distance to the rear of the panel member 22 to enable the angular edges 20a and 2la of this tongue to engage side edges of the slot l8 when thetongue lBis twisted side-wise into the position shown in Figure 2, to support the resistance unit.

When the tongues l6 and I! are twisted sidewise to the positions shown in Figure.2, the angular edges thereof engage side edges of the slots l8 readily transferred to, the supporting panel '22,.

and I9, respectively, and produce a cam-like action which draws the base of the resistance unit easing into firm contact with surfaces of the panel 22. If the tongues l6 and I! are twisted sufliciently, the resistance unit will be held in place against the supporting member 22 so that severe vibration of this supporting member will not \ioosen the resistance unit and cause it to vibrate with respect to said supporting member. The casing of the resistance unit is thus supported in firm contact with the support 22 and heat developed in the resistance .unit may be thus permitting the resistance lunit to ated at a lower temperature. Y

In Figure 4 I have shown a slightly modified form of this invention in which the mounting be opertongue iSis made of smaller size than that shown in Figure 2, for example. Both tongues may be made in this manner where the holes iia and "a are to be eliminated from the tongues l6 and l I, respectively. The purpose of these holes 16a and [1a is to permit the resistance unit to be mounted with small bolts if desired. These holes also may serve to're'ceive a rod-like tool for the purpose of twisting the tongues l6 and I I sidewise. Otherwise the tongues may be twisted by means of pliers, vices, or. other tools. In Figures 5 and 6 I have shown the jacket or casing blanks Hid prior to bending, The longitudinal side portions of these blanks are bent over the resistance unit winding l2, insulation wrapper l3, and terminals II and I! so that the casing formed of the blank Illa, houses the com' leted resistance winding} The resistance windi g I! is wound upon a. core l2a of suitable material. Where desired, the tongue supports l6 and I! of my invention may be provided to resistance units encased in troughlike members such as disclosed in application Serial No. 75,179 of Karl E. Rollefson and in that case, if desired, the tongues" l8 and I1 may be punched by a punch press or other suitable machine from the bottom of the trough-like casing if it is not convenientto provide these tongues at the ends of the casing; This procedure may be employed to save material from which the blanks Illa are made and if desired, the tongues I6 and I! may be cut from the inner body portion of these blanks instead of being made at the ends of the blanks.

While I have described this invention in detail with respect to certain embodiments thereof, it is, of course, understood that modifications within the scope and spirit of this invention may be made without departing therefrom and therefore I do not desireto limit the invention to the exact details shown except insofar as they are defined by the claims.

What I claim and desire to secure by Letters Patent of the United States is as follows:

1. A resistance unit casing of the type adapted to be used on resistance units suited for use in amplifying apparatus comprising a blank of elongated, substantially rectangular body portion, substantially parallel, longitudinal sections of the sides of said blank being adapted to be folded over a resistance element to embrace said resistance element, a pair of tongue-like elements extending from the ends of said blank, said tongue-like elements havingthe edges of the sides thereof diverging .to form wedge-like elements adapted to be bent downward with respect to said blank body portion to be received in slots and engage sides of said slots in cam-like fashion.

2. A resistance unit casing of the type adapted to be used on resistance units suited for use in amplifying apparatus comprising a blank of elongated, substantially rectangular body portion, substantially parallel, longitudinal sections of the sides of said blank being adapted to be folded over a resistance element to embrace said resistance element, a pair of tongue-like elements extending from the ends of said blank, said tongue-like elements having wedge-like sections cut out of opposite sides thereof to decrease the width of said elements and facilitate bending of said tongue-like elements downward with respect to said blank body portion to be received in slots and engage sides of said slotsin cam-like fashion.

3. A resistance unit casing'of the type adapted to be used on resistance units suited for use in amplifying apparatus comprising a blank of elongated, substantially rectangular body por- 4; A resistance unit of the type adapted to be used in amplifying apparatus comprising a resistance element, an elongated sheet-like metallic member for snugly engaging said resistance element, said resistance element having a terminal thereof connected to said sheet-like metallic member, a metallic panel support adapted to form one of the circuitconnections to said resistance element through'said terminal, and

means for supporting said sheet-like metallic .member on said metallic panel support, saidmeans including 'tongue means formed integral with said sheet-like metallic member and having wedge-like surfaces to engage .slots formed in said metallic support and draw and hold said metallic member to said metallic panel support under tension by a cam-like action to prevent said resistance element from shaking with re spect to said metallic panel support.

5. A resistance unit of the type adapted for use in amplifying apparatus, comprising a resistance element, an elongated metallic member for snugly holding said resistance element and having means for fastening said resistance element to a substantially flat metal support, said means comprising tongues formed integral with said elongated metallic member and tapered sides for engaging the sides of slots formed in said metal support and for drawing said metallic member and said resistance element tightly and firmly against said metal support by a sliding and gradual cam-like action when each of said tongues is twisted with respect to he longitudinal axis of the corresponding slot, said tapered sides of said tongues being formed in such a way that said fastening means may be employed with substantially flat supports of substantially different thicknesses.

LESLIE F. MUTER. 

